Ya im actually up in Tallahassee so im a good 4 to 5 hrs away from tampa unfortunately. Ya i read a couple posts where some people's pd would not make noises. I find that interesting for the fact that the minute i walk into my room mine wont stop haha. Hes about 3 months old now so that is weird that yours wont make noises.
I got a rescue boy in a about a year ago who didn't make any noises either, and he was at least a year old. It took a few months of hearing my other prairie dogs, and me talking to him, for him to learn. I think it also has a lot to do with them feeling comfortable in their surroundings. Your guy will figure it out eventually.